Clarify the How-To's for multi-server setup

I love your guys' howto's and they are simple to follow, for someone like myself. However when setting up the servers, I have tried to apply for example the below How-To to a multi-server setup. Would it be possible to add some type of tags such as [web], [mail], [db], etc for what needs to be installed where?

For example. I am confused where Mailman needs to be installed. Is it something that needs to be installed on the Web server or the Mail server?

This would somewhat eliminate the needs for individual multi server setup instructions. I think.

Multi servers etups are different from the perfect setup, thats why they exist as separate tutorials. So you just used the wrong guide (a singl servers etup) instead one of the multiserver guides. All Multiserver tutorials are listed here: